testsuite: Add compile-fail test for #5883

src/test/compile-fail/issue-5883.rs

+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::io;
+
+struct Struct {
+    r: io::Reader //~ ERROR reference to trait `io::Reader` where a type is expected
+}
+
+fn new_struct(r: io::Reader) -> Struct { //~ ERROR reference to trait `io::Reader` where a type is expected
+    Struct { r: r }
+}
+
+trait Curve {}
+enum E {X(Curve)} //~ ERROR reference to trait `Curve` where a type is expected
+fn main() {}